A 4,000-year-old defensive wall in Morocco points to a more advanced ancient North Africa

On a ridge above the Oued Beht river in north-west Morocco, excavators have exposed a defensive structure that radiocarbon dating places at roughly 4,000 years old. Giulio Lucarini and colleagues call it the earliest known large-scale construction of a probably defensive nature in North Africa beyond the Nile Valley. The site lies in Khémisset Province, and the fieldwork described here took place in October and November 2023.

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The finding matters because it suggests a more advanced ancient North Africa than the textbook picture of scattered farming villages. A ditch, an embankment and a massive stone wall imply that people at the site could plan, quarry and coordinate labor on a scale usually credited to later or better-known cultures.

Radiocarbon dates and the Oued Beht construction sequence

The results appear in Libyan Studies, the journal that published the third-season report of the Oued Beht Archaeological Project. Seventeen radiocarbon dates came from the main trench, and 15 were judged reliable. Charcoal from the foundation of the earliest wall returned a range of 2010 to 1747 BC, and seeds from later contexts fall between about 1729 and 1324 BC. Taken as a set, the dates put construction in the early to middle second millennium BC, which is about 3,500 to 4,000 years ago, and mark the first evidence of activity at the site in that millennium. The project brings together researchers from Italy’s National Research Council in Rome, the McDonald Institute for Archaeological Research at the University of Cambridge and Morocco’s National Institute of Archaeological Sciences and Heritage in Rabat, with Cyprian Broodbank and Lucarini as corresponding authors.

French archaeologist Armand Ruhlmann had described the ridge in the 1930s as an “éperon barré”, a promontory sealed by walls with a natural scarp as the fourth side. Their exact nature and date stayed uncertain until the new excavations, according to the ScienceDaily version of the team’s own account.

Wall B1: limestone blocks, 2.3 meters wide

The journal article describes Wall B1 as by far the most massive of four east-west alignments in the southern sector. Built of limestone blocks and cobbles in a compacted earth matrix, it stands about 1.35 meters high and 2.3 meters wide at ground level. Blocks run up to three courses deep and mostly measure 39 to 55 centimeters along the long axis, set on a foundation cut about 35 centimeters wide. Beneath it lay an earlier wall of daub and charcoal-rich silt resting on gravel, so the defense was rebuilt and enlarged at least once. The trench that exposed the wall measured 14.2 meters long and 2.5 meters wide, a narrow window onto a structure whose full length remains unreported. A smaller single-course stone wall without evident mortar sat nearby and may have retained soil.

Alongside the stone sat an embankment with three construction phases and a posthole that probably held a structural timber. A ditch dug beneath the visible masonry, described by Finestre sull’Arte, blocked the southern end of the settlement and used the natural shape of the ridge.

Grain pits and a settlement of about ten hectares

The settlement behind the barrier covers roughly ten hectares and dates from the mid-fourth to early third millennium BC, according to ArchaeologyMag. Dozens of bell-shaped pits likely held grain, and their number suggests storage beyond what a local community needed. Reporting in Live Science describes an early farming hub with livestock, crops and large-scale storage, which is the kind of stockpile worth defending. Lucarini and colleagues read the combination of surplus storage, a deliberate ditch and a multi-phase stone wall as evidence of organized communities rather than isolated hamlets, though the radiocarbon sequence still leaves the exact year of each phase open.

A later medieval stone wall overlooks the older earthwork, and a medieval cemetery was found nearby, so the ridge stayed in use long after its prehistoric builders. Radiocarbon on a seed from the medieval layer points to the 11th or 12th century AD, which gives the hill roughly three thousand years of intermittent occupation.

Planning, competition and the case against imported ideas

Lucarini told Live Science the project demanded “planning, choosing the right spot in the topography, and mobilising and coordinating labour over time.” He doubted that simple invaders explain the barrier, and instead pointed to growing competition over land and resources, control of movement, or more formal leadership. Iman Nagy, a UCLA landscape archaeologist who was not involved, said the find challenges models that assume complex architecture must have arrived from elsewhere.

Scale keeps the claim modest. Contemporary Iberian sites were larger fortified hilltop settlements with planned architecture and social hierarchy, and Oued Beht’s defenses look much smaller. The open question is how the ridge relates to other undiscovered settlements nearby, a gap that later seasons of the Oued Beht project are meant to narrow. Lucarini and his co-authors argue in the journal that the site is important for revising long-term settlement patterns in north-west Morocco and for understanding Mediterranean interactions, a claim that rests on chronology still being tested trench by trench.

This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.

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